Sandisk 32GB Class 4 MicroSD MicroSDHC Memory Card Compatible with AT&T Sonim XP7 Cell Phones. As smartphones with card slots become increasingly popular, it's important to have a SanDisk micro Secure Digital (microSDHC) Memory Card to help you get the most out of your phone. Your phone with a card slot goes everywhere you do, so you should put it to good use. With a SanDisk microSDHC Memory Card, you instantly add more memory storage so you can fit more on your phone with a card slot--music, videos, ringtones, games, apps, and more. And to help you organize all your media files so you can easily transfer them back and forth between your phone and PC, SanDisk offers a free Media Manager software download.